In the early days of The Smashing Pumpkins, Billy played a ~1965 Fender Mustang (Red), he can be seen playing this red Mustang on the 1988 Pulse Basement Jam cable show.

From an interview on Fender.com (Nov 21, 2009) - Billy states: "Well, my first real guitar was a Fender Mustang. It was more of an economic thing—I couldn’t really afford any other guitar, and I think I got it for a couple hundred bucks. And I always loved that it had this sort of Indian thing—you know, there wasn’t a lot of sustain on the guitar, and I think in my early playing I was sort of attracted to that kind of Cure style of playing, even though I didn’t know the Cure existed—but that sort of open-string-y type thing. So in the early days of the band, that’s what I played, but I could never get the gain that I wanted."